Magnetic powder dispenser



Jan. 26, 1960 H. E. KENNEDY MAGNETIC POWDER DISPENSER Original Filed Feb. 17, 1955 INVENTOR HARRY E KENNEDY jZ V MAGNETIC rownER' DI PEN R Harry E. Kennedy, Berkeley, Calif assignor to Union Carbide Corporation, azcorporation of New York Continuation of abandoned V application Serial No.

488,820, February 17, 1955. This application Janu ary 16, 1957, Serial No. 634,584

8 Claims. (Cl. 302-51) The present invention relates to novel apparatus for suspending in a stream of carrier gas a powdered welding composition having a magnetic component.

a In my co-pending patent application Serial No. 481,906, nowpabandoned, entitled Welding Process Employing Shielded Metal Arc," a process is disclosed wherein a powdered non-gas-evolving mineral material containing a magnetic component is suspended in a stream of shielding gas and conveyed therein to a point adjacent to the arcing end of a current-carrying consumable metal welding electrode, to which it adheres. The shielding gas, after conveying the powdered magnetic coating to the rod, is distributed about the arc zone in such a manner that itserves to shield thewelding zone and the weld puddle from the air'of the atmosphere. The powdered mineral material is a fused, bonded composite and contains a magnetic component which may comprise any suitable ferromagnetic material, such as iron powder or a powdered ferrite, wherebythe powdered composite material is .caused to adhere to the surface of a current-carrying or a permanently magnetic body;

It is the main object of the present invention to provide simple and rugged apparatus suitable for uniformly suspending powdered composite. welding composition having a magnetic component a stream of shielding gas at a.

controllable rate. 7

According'to the-presentiinvention, the apparatus for suspending in a stream of carrier gas powdered material having a magnetic component comprises regulator means for controlling-the discharge of said material from a 'supply thereof, magnetic conveyor means receiving said discharged material fromsaid regulator, means, and suspending gas conduit means receiving said conveyed material from said magnetic means. means comprises a tube receiving the material from a hopper, and the magnetic conveyor preferably comprises a magnetic-surface movable under the tube, the'tube being vertically adjustable to regulate the distance above the surfaceqfor the discharge orifice at the bottom of the tube, to deposit on the surface a layer of material of thus determined uniform thickness. The material is removed from the conveyor preferably by wiper means, and dis charged into the suspending gas conduit means.

In the drawing:

Figure 1 is a vertical sectional view of a magnetic powder: dispenser embodying the invention;

Figure 2 is a partial sectional view of the dispenser taken along the line 22 of Figure 1;

Figure 3 is a partial sectional view of the dispenser taken along the line 3-3 of Figure 2; and

Figure 4 is a partial elevated view of the dispenser taken along the line 44 of Figure 2 and showing in detail a part of the vibrator and magnetic drum drive mechanism.

In the preferred embodiment of the present invention shown in the drawings, apparatus for suspending powdered composite magnetic material in a stream of gas is provided having a closed material hopper discharging,

Preferably the regulator atent Patented Jan. 26, 1960 ice under the influence of gravity, into a com'municating distributing chamber-having positioned therein a rotating magnetic drum. The powdered magnetic material enter-- ing the distributing chamber adheres to and builds up as a layer on the surface of the rotating magnetic drum. As the drum rotates to a point approximately one half a turn beyond the point of material deposition, a scraper removes the material-from the drum and the material passes, under port means 14. The top of hopper 10 is provided with a hopper fill plug 16 for supplying powdered material to the hopper. V V

Regulating tube means 18 is provided in hopper 10 and extends from the hopper to a point at which manual adjustment can be made. prises an elongated hollow cylindrical tube provided at the upper end thereof with threads 20 and a knob 22 for rotating the tube. Threads 20 are engaged in the top 24 of hopper 10, and the position of regulating tube 18 can 7 be raised or lowered by turning knob 22. The lower end of regulating tube 18 passes through discharge port means 14 and contains passages 26 communicating between the lower portion of hopper 10 and the interior 28 of regulating tube 18, through which powdered material is passed from the interior of hopper 10 to the interior 28 of regulating tube 18. V V V A material distributing chamber block 30 having a closed distributing chamber 32 is positioned below hopper 10 so that chamber 32 is in communication with thedischarge end of interior 28 of regulating tube'18. A rotating magnetic drum 34 is positioned in chamber 32, below the'discharge end of regulating tube 18, so as to receive the powdered material discharging therefrom. The pow- 1 dered material builds up to form a coating 36 on the sur-.

ing knob 22 of regulating tube 18 to vary the longitudinal positioning ofthe regulating tube. Material wiping means 42 is positioned in chamber 32 below rotating magnetic drum 34 so as toremove the coating of powdered material from the drum and allow it to pass, under the influence of gravity, through outlet passage means 44 of the distributing chamber 32. V

The powdered material passes through conduit means '46 into injector chamber 48, into which a stream of carrier gas is injected at high velocity from injector 50 (communicatingwith inlet gas conduit means 52). The powdered material suspended in the gas stream in chamber 48 is discharged throughoutlet conduit means 54 to the point'of intended use. 7

Theinterior of closed hopper 10 and closed distributing chamber 32 is at a positive pressure of gas established by the backpressure in the system from the gas conduit. A pressure equalizing line may be run from the carrier gas conduit 52 to the hopper 10, if desired.

Vibrating means is provided for preventing clogging of the powdered material in the hopper and insuring a uniform rate of flow of material from the hopper through regulating tube 18. As shown in Figures 2-4 of the drawing, driving means is provided comprising a driving chain 56 and a driven sprocket 58 which, in turn, drives both The regulating tube 18 com which actuates. hammer fid-tagainst springg616 so. astto;

deliver im-pact; to; anvilz6,& rigidly; mounted on the dis-,

tributing; chamber :bloekdzl); Thisevibrationt delivered; to; the dist-ributing;chamber-. block 30 is rtransmittedgto hop per. lllrwhichtis;securelymountedthereon.

Shaft 60 is also; mounted to -drive rotatmgmagnetic,

drum,- 34'within chamber 32. The. rotating magnetic drum;comprisesapermanentmagnet 70A enclosed in an outer casing 72 -offerromagnetic; material, such as steel,', whereby; the magnetic circuit is completed to; the;pow-

dered magnetic material deposited-onthe surface. 3.8;.of magnetic. drum 3.4;

Anelectric holding coil; 76; is provided; around; discharge port means 14 of hopper 10 so as to; surround the passages .26 of; regulating tube 18. Coil. 7 6 is energizedv when norpowdered, magnetic material; is needed, thereby; stopping, the passage; of; material through tube 18-.to ,chamber- 32v and'preventingtheflooding of chamber 32 with powdered material.

It:has:. been. found, that; the powder dispenser, of. the invention is capable of very closely regulating therate of feed ofpowdered magnetic material from the hopper tothe. carrier gas stream and thereby uniformly distributing powdered magnetic material inthecarrier gas stream. Means are provided for, easily insuring against failure in the supply of powdered magnetic material which, if it occurred, would necessitate a stoppage in the welding operation, in which; the gas-borne powdered. magnetic material, isgutilized;

A dispenser of the type shown ;in the drawing was employed to suspend powderediwelding compositionin a stream ofcarbon dioxide carrier; gas atpowderfiow rates of. between about 10 and-l50k grams perminute. This dispenser employed aregulatingtubehaving: three passages 1 /2 inches X 1% inches an internahdiameterof inch andclearance of inch.between,the discharge end of theregulating tube and thesurface of. themagnetic drum. over .a, carrier gasfeed'rate of from about 5-to1510. c.f;h., withzabouti c.f.h. the minimum-operable gasflowratefor satisfactorily suspending finely powdered; material (100x13), and'about -15 c;f;h; theminimumzoperable gas flow rate for satisfactorily suspending. coarser'particles (XD).

This. application isa-continuation of my copending applicationSerial No. 488,820-filed,February 17, 1955, now abandoned.

What is claimed is:' I

1. Inapparatus for; suspendingin: a;stream of'carrier gasa powdered composite material. having a magnetic component including; a material hopper communicating at the base with discharge: P.Qrt;me ans, a material distributing chamber. in a communication; with said discharge. port means and having an outlet passage,. and:.suspending gas conduit means. in communication: with; said. outlet passage, the. improvement ,which comprises magnetic. conveyorimeans in said distributing chamber, horizontal orifice means-positioned .above'said magnetic conveyormeans for, discharging at quantity of said composite material onto the surface of said magnetic .conveyontoaformtthereon a rectangular layer of said composite material ofuniform thickness, and means, for. regulating; the-vertical clearance between saidhorizontal orificemeansand said magnetic conveyor means to adjust-thethickness. of said rectangular. layer, and -means for removing. said layer of composite material .fromsaid, magnetic conveyor and .dis-

charging it \to said .outlet passage.

2. Apparatus in; accordancewith. claim. 1, in which It was found-that this dispenser was operable such vibrations. are transmitted to. said. hopper for. preventing the clogging of said .material therein.

3. A distributing chamber having an inlet passage for discharging from a supply and a vertically aligned outlet delivering to a carrier gas stream suspension conduit a powdered composite materiaLlIaViHg a magnetic component, comprising magnetic conveyor means, mounted in said chamber, a hollow regulator tube extending from above into said chamber; to.-a variable height, above said? magnetic; conveyor "means :for discharging from said inlet a controlled quantity. of said material onto saidtmagnetic. conveyor, means. to form thereon-1a continuous-layer of said material, and Wiper meansfor. removing said layer from said magnetic conveyor means and passing it through said vertically'aligned outletpassage to said carrier gas stream suspension conduit.

4. A distributing chamber for discharging from a supplyiand; delivering to a. carrierxgas stream.suspensionvconduit. av powdered: composite Lmaterial= having: a; magnetie component, comprising;- magnetic conveyor means: mounted'in-said: chamber, ahollow. regulator tube extending from; above into said chamberto at variable-- height above said:magnetic.conveyor meansfor discharging: a..controlledquantity. of said materialonto .said magnetioconveyor means to formzthereon a continuous layer of. said material, wiper; means;for removing said layer from. said; magnetic conveyor means andxpassing it: to: said carrier. gas stream suspension conduit, and meansfor' vibrating saidchamber to prevent cloggingofisaid' com-- posite material.

5; In apparatusefor suspendinginaasstream of carrier gas atpowdered'composite material having a ferromagneticcomponent including. a closedmaten'al hopper com rotating. magnetic drum; means to :collect thereona layer of 'saidcomposite material; and drum wiper means positionedat andcontacting the lower portionof said magnetic. drum means for Wipingsaid collected layer of com-- posite material from said: rotating magnetic drum means andpermitting. itto passunder gravityto said outletu passages.

6. .Inapparatus for suspending in a:stream.of carrier gas a powdered .composite material having aterromagnetie component including a closed material hopper communicatingatits basewith discharge .port means, a closed -ma-- terial distributing. chamber in communication withsaid dischargeport meansand having at itsbase-an outletpassage,.and suspending: gas conduit means in communication with said Joutletpassage for suspending -said com-- posite material. in a stream. ofcarrier gas conducted therethrough; the improvement which comprises magnetic drum means rotatably mounted in said distributing chamber, regulator tube means positioned in saidhopper 'and extending. through said discharge port means for discharging a controlled quantity of said -composite material onlthe surface of said rotating magnetic drum' to collect thereon a layer of saidcomposite -material, aninjectorv chamber including-a gas injector in said suspending gas conduit means :for suspending said composite material, in .acarrierrgas streamg and drum-wiper meanspositioned at and contacting the lower portionof' said magnetic drum-means for wiping: said-collected layer of compositermaterial from saidirotating magnetic drum' and. permittingcit: to pass. under: gravity tosaid" outlet passages.

7. A distributing chamber for discharging from a hopper supply and delivering to a carrier gas stream suspension conduit a powdered composite material having a ferromagnetic component comprising a magnetic drum rotatably mounted in said chamber, a hollow regulator tube extending from above into said chamber to a variable height above said rotating drum for discharging a controlled quantity of said composite material on the surface of said drum to collect thereon a continuous layer of said composite material, and drum wiper means positioned at and contacting the lower portion of said magnetic drum for wiping said collected layer of composite material from said drum and allowing it to pass under gravity to the carrier gas stream suspension conduit.

8. In apparatus for suspending in a stream of carrier gas a powdered material having a magnetic component, means for supplying said material, regulator means for controlling the discharge of said material from said sup- References Cited in the file of this patent UNITED STATES PATENTS 1,110,926 Greenstreet Sept. 15, 1914 1,407,600 Stehli Feb. 21, 1922 1,971,376 Hunt Aug. 28, 1934 1,993,249 Scholz Mar. 5, 1935 2,108,416 Smith Feb. 15, 1938 2,323,786 Beisel July 6, 1943 2,587,609 Fischer Mar. 4, 1952 

